Boris Johnson took office on 24 July 2019. At first, Dominic Cummings, his political strategist, advised him to ignore the civil service “babbling” on Northern Ireland. Ignoring Brexit trade-offs and just getting it done required audacity instead of Theresa May's prudence, it seemed, and the approach during Johnson's first weeks in office aimed to make the EU budge and ditch the backstop. Mid-September that approach changed. Johnson's negotiator David Frost transmitted confidential papers to Barnier's team. At first, they just rehashed the alternative arrangements, aspiring to find vague solutions at an undefined moment in the future. EU experts chewed over the written material, which changed the dynamics of the talks from a sterile confrontation to probing the feasibility of UK ideas on customs and regulatory checks of food and manufactured goods. In a surprise announcement, Johnson's Conservative Party conference speech in Manchester proposed an all-island solution for regulatory compliance with EU standards for manufactured goods and accepted to treat Northern Ireland differently from the rest of the UK well before the endgame of negotiations.

Act 1: a cordial confrontation

In early July, Boris Johnson and Jeremy Hunt went head-to-head in the Tory leadership battle. Hunt stated the backstop had to change or go but added that a no-deal Brexit would be suicidal, which was a softer line than Johnson's “ditch the backstop” pledge and leave on 31 October, come what may. There was no need for this pledge to clinch the leadership contest, as few doubted Johnson would win. It looked as if he was setting himself up for confrontation.

There was speculation in Westminster whom Johnson would appoint as Brexit negotiator. Barnier was curious to understand the profile of the new prime ministerial team as a sign of where the story could go next after the bellicose rhetoric of the campaign. David Frost, whom Johnson appointed, was an enigma, however. He had experience in EU affairs. Frost had worked for the Foreign Office and been a diplomat in Brussels, representing the UK in the trade policy committee. Afterwards he was ambassador to Denmark. EU and Danish officials who knew him in those capacities mentioned his strong Euroscepticism. But outside of government, he had worked for the Scotch Whisky Association, which lobbied traditionally for a deepening of the EU single market and an ambitious EU trade policy to gain easier market access around the world.